HYDROCARBONS 349 



hydrocarbon. More recently, Young'^'''-^^ reported that a levorotatory 

 diol was excreted by rats which had been given naphthalene orally or 

 subcutaneously. This diol was identified as l,2-dihydronaphthalene-l,2- 

 diol. When decomposed with acid, this diol gives rise to a-naphthol.-®^ 



\ 



1 ,2-Dihydronaphthalene 

 trans-l, 2-diol 



The Conversion of 1,2-Dihydronaphthalene-l, 2-diol to a-Naphthol b}' Heating in the 



Presence of Mineral Acid^*' 



This diol has been shown to have the trans configuration. ^^^-^^^ It has 

 likewise been demonstrated by Boyland and Wiltshire"'' that naphthalene 

 is slowly converted to l,2-dihydroxy-l,2-dihydronaphthalene by liver 

 slices; however, there was no evidence for the formation of a-naphthol. 

 The rate of the in vitro reaction was of sufficient magnitude to account for 

 the metabolic production of the diol in rats. 



e'. Resume of the Metabolism of Naphthalene: The metabolism of 

 naphthalene resembles that of benzene in the formation of a-naphthol, 

 which is detoxicated and excreted both as the glucuronide and as the 

 ethereal sulfate. A further resemblance in the metabolic pathway of 

 benzene and of naphthalene is in their formation of mercapturic acids. 

 On the other hand, no unchanged naphthalene is excreted, as occurs with 

 benzene. Moreover, there is no e\ddence of rupture of the aromatic ring 

 in the case of naphthalene, such as occurs when benzene is broken down to 

 muconic acid. A further dissimilarity is in the partial saturation of the 

 naphthalene nucleus concomitantly with the formation of the monohy- 

 droxy or dihydroxy compounds. These metabolic products are 1,2-di- 

 hydro-2-naphthol and l,2-dihydroxy-l,2-dihydronaphthalene. a-Naph- 

 thaquinone has also been cited as a metabolite of naphthalene. Although 



2«« L.Young, Can. Chern. Process Inds., 30, 124 (194G). 



^' L. Young, The Oxidation of Polycyclic Hydrocarbons in the Animal Body, in R. T. 

 Williams, Biological Oxidation of Aromatic Rings, Biochem. Soc. Symposia, No. 5, Cam- 

 bridge Univ. Press, 27-39 (1950). 



^^ J. W. Cook, J. D. Loudon, and W. F. Williamson, S6th Kept. Brit. Empire Cancer 

 Caynpaign, p. 249 (1949); cited by L. Young, The Oxidation of Polycyclic Hydrocarbons in 

 the Animal Body, in R. T. Williams, Biological Oxidation of Aromatic Rings, Biochem. 

 Soc. Symposia, No. 5, Cambridge Univ. Press, 27-39 (1950), p. 35. 



^^ J. Booth and E. Boyland, Biochem. J., U, 361-365 (1949). 



2™ E. Boyland and G. H. Wiltshire, Biochem. J., 53, 424-426 (1953). 



